Abstract

Monoactivated derivatives of 1,1-dihydroperoxides undergo an unprecedented base-promoted fragmentation to efficiently generate singlet oxygen (1O2) in anhydrous organic solvents. Singlet molecular oxygen (1O2), an important oxidant in chemistry, biology, and medicine, 1a,b is most commonly generated via photosensitized excitation of ground state (3O2) dioxygen. 1b,2 The discovery that 1O2 is also produced from reaction of H2O2 and HOCl led to the discovery of a number of additional methods for chemical generation.1a,3,4 However, many of these “dark ” oxygenations have significant limitations. Due to the short half-life of 1O2 in aqueous media,5 methods based upon reaction of H2O2 with hypohalites,3 alkaline earth metals, 6 transition metals,7 lanthanides,8 or metalloenzymes9 must typically employ biphasic or emulsion conditions for preparative oxidations.10 Thermal generation of 1O2 from phosphite ozonides,11 silyl hydrotrioxides,12 or arene endoperoxides13 can be conducted in organic solvents but requires preparation of unstable precursors. We report an efficient and convenient generation of 1O2 in organic solvents via an unprecedented fragmentation of derivatives of